The name is so closely associated with Scotland that it seems part of the very fabric of the nation. Whisky, bagpipes, red deer stags, porridge, heather: each might seem to have aspects of cliché or stereotype about them, but each is also of great value (in widely different ways) to the country.

Scots pine and heather. © Lorne Gill/SNH

Wide moors that flush purple in late summer and early autumn – and have a slow fade to the tawny tones of winter – owe their colour, fundamentally, to heather.

‘Heather’ can refer to any of three small, woody heathland plants, each adding their own tints to this palette. Cross-leaved heath is pale and salmon coloured. Bell heather has a hotter pink. And ling – the commonest small shrub of the Scottish moors – is pale purple-pink. It’s ling or ‘common heather’, more than the others, which is the plant most people know simply as ‘heather’.

Large areas of upland Scotland – particularly in Perthshire, the Cairngorms, Deeside and the Borders – are dominated by ling. In these places, the mass of flowers spread across many hectares of moor in August and September is unmistakable; their blush is the dominant colour at ground level. In other places and at other times, you might see fewer plants or less punchy colour. That’s when you need to look more closely to identify ling and related moorland plants.

Ling is a bushy shrub that can typically grow up to about 60 cm high in places where heathland is ‘managed’ through grazing and/or periodic burning. Where moors aren’t managed, it can grow even taller. Close-up, look for many side shoots along the twiggy stems. These are packed with rows of narrow leaves, each row opposite one on the other side of the shoot. Leaves in cross-leaved heath and bell heather are arranged in whorls up the stem.

Ling flowers can be packed together quite densely along leafy spikes in the upper part of the plant. Each purple-pink petal tube is shaped like a tiny bell (more bell-like, in fact, than bell heather flowers, which are more tubular in shape).

Bell heather (Erica cinerea). ©Lorne Gill/SNH

Heather occurs in many parts of Scotland, sometimes as an occasional plant sprouting among other vegetation – for instance, in grasslands where the soil is fairly acidic. However, the prime areas for heather are the uplands, where heathland cover (much of it with ling present or abundant) is internationally important.

Scotland is the European stronghold for upland, heather-rich heath, with about a quarter of the whole surface of the country covered in it. Both wet and dry types of heather moor grow here, each with a slightly different mix of other plants that grow with common heather. The wet moors are commonest in western and northern hill areas, where drainage may be poor and rainfall high. Dry moors are commoner elsewhere, including the heather moorland heartlands of the central and eastern Highlands and the Borders.

Woodland clearings could be considered the ancient home of heather. That’s where it can be part of an unfolding sequence of vegetation that moves in to cover ground laid bare by fire (such as after lightning strikes) or exposed to extra sunlight when trees are blown over (after storms). However, man has been giving a boost to heather for a very long time, especially through using patterns of grazing and burning that favour it over grasses and trees. In Scotland, the amount of heather has gone up and down, linked to human activity, over many hundreds of years.

Heather. ©Laurie Campbell/SNH

The most distinctive heather moors are in drier uplands, where a characteristic pattern of burning strips on grouse moors is used to boost the growth of young heather. Other stages of the plant are kept as cover for nesting grouse and their broods. Typically, each of these strips is torched every 10 to 15 years. The practice of burning not too often and not too hot removes old stems but keeps the roots alive. These roots can then support fresh, food-rich young shoots, which are now free from competition with competing trees, as these will have been killed or suppressed by the fire.

In the past, heather was used for many different purposes. For instance, the people who lived in the Neolithic settlement at Skara Brae on Orkney, many thousands of years ago, twisted the tough stems to make ropes. Large balls of heather rope could be used to secure thatch and the stems were packed in as insulation inside cavity walls. Other uses included brooms and basket handles.

The best time to line a box bed with heather was after harvesting when the heather was in full bloom. After being spread out to dry for a few hours, the material was packed with all the flowering heads upright and leaning a little towards the head of the bed. Held in by logs at its edges, the finished product was said to look like a field of purple bending in a breeze. It might also give out a honeyed, sleep-inducing perfume, which provided quite a mattress for use in a peasant’s cottage.

Heather would continue to grow in many places – including the woodland clearings that are its natural home, so to speak – without people’s help. But the large, heather-rich moors that are famous for both their colour and extent owe their continuing presence to human action.

Many of these moors would, through natural processes, become woodlands if they weren’t regularly burnt to promote the regeneration of heather. It would survive in open areas there, but it wouldn’t be the dominant plant across a whole landscape. So in that sense, heather moorlands are very strongly linked to human activity.

The action with the most obvious heather boosting effect is grouse moor management. This also produces the distinctively patterned, multi-toned strips on hillsides. Elsewhere, a different kind of ‘muirburn’ to promote fresh growth of grasses may also maintain some heather.

So if we’re to continue having large areas of heather in Scotland, then very careful muirburn (now governed by law and through codes of practice) is essential. People are also trying to keep Scottish heather in the pink (or purple) through research into how different amounts of grazing affect heather cover, along with advice to different kinds of upland managers.

Seasonal scenes

Spring

Where buds at the ends of long ‘leading’ shoots have survived the winter, these are usually the first to break into new growth in spring. Where those buds have died, ones on shorter shoots might sprout first. The fresh leaves are bright green and widely spaced, in strong contrast to the dull, densely packed foliage from the previous year’s growth.

Summer

Fresh shoots continue to grow.

Autumn

August and September are peak times for vibrant heather colour on Scottish moors. The timing of peak colour varies from year to year, depending on the weather conditions in both spring and summer.

Winter

Growth stops and plants become dormant. This includes buds that will, with luck, survive until the following spring and be able to send out fresh shoots.

Further reading – Plantlife page on heather http://www.plantlife.org.uk/wild_plants/plant_species/heather/